福井 康祐, 浅見 忠男
化学と生物
2012年
50 巻
8 号
562-563
発行日: 2012/08/01
公開日: 2013/08/01
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フリー
来生 貴也, 謝 肖男, 金 賢一, 米山 香織, 佐渡 愛香, 秋山 康紀, 林 英雄, 内田 健一, 横田 孝雄, 野村 崇人, 米山 弘一
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金 賢一, 謝 肖男, 米山 香織, 来生 貴也, 野村 崇人, 米山 弘一
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来生 貴也, 謝 肖男, 米山 香織, 内田 健一, 横田 孝雄, 野村 崇人, 米山 弘一
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Previously, we reported that dokudami (Houttuynia cordata Thunb.) produce 5 known strigolactones (SLs), strigol, sorgomol, ent-2'-epiorobanchyl acetate, fabacyl acetate and 5-deoxystrigol, and novel SLs. HR-MS analyses of novel SLs revealed that their molecular are the same to that of strigol. One of them was suggested to be a positional isomer of strigol by 'H-NMR analysis. In addition to these SLs, presence of other novel SLs was indicated by bioassay-guided fractionation.
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来生 貴也, 中谷 成史, 謝 肖男, 米山 香織, 秋山 康紀, 林 英雄, 内田 健一, 横田 孝雄, 野村 崇人, 米山 弘一
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笹瀬 えりな, 米山 香織, 石井 裕紀, Eloise Foo, Cassandra Hugill, Laura Quittenden, James B. Reid, 米山 弘一
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謝 肖男, 米山 香織, 来生 貴也, 内田 健一, 伊藤 誠祐, 秋山 康紀, 林 英雄, 横田 孝雄, 野村 崇人, 米山 弘一
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久嶋 秋美, 来生 貴也, 謝 肖男, 米山 香織, 内田 健一, Monica Fernandez-Aparicio, Diego Rubiales, 横田 孝雄, 野村 崇人, 米山 弘一
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Broomrapes (Orobanche spp.) cause significant losses to agricultural production all over the world. The seeds of these parasites germinate only when they are exposed to the germination stimulants including strigolactones (SLs) produced by and released from host roots. In this study, characterization of strigolactones produced by faba bean (Vicia faba), a host of O. crenata and O. foetida was conducted. Faba bean was found to produce orobanchol and ent-2'-epiorobanchyl acetate by LC-MS/MS analysis of root exudates. Bioassay-guided purification to isolate novel germination stimulants is in progress.
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米山 香織, 石本 圭子, 謝 肖男, 生木 貴也, 朝比奈 雅志, 野村 崇人, 竹内 安智, 米山 弘一, 横田 孝雄
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Striga spp., devastating root parasitic weeds, attack monocot crops including sorghum, millet and maize in semi-arid tropics. Their seeds require germination stimulants (mainly strigolactone, SL) released from host roots to germinate. In the present study, characterization of SLs in the root exudates from maize plants including the Striga susceptible cultivar Pioneer 3253 and tolerant cultivars KST94 and WH502, grown hydroponically was conducted by comparing retention times of germination stimulants on reversed phase HPLC with those of synthetic standards and by using LC/MS/MS. The susceptible cultivar mainly exuded larger amounts of 5-deoxystrigol and the tolerant cultivars exuded mainly strigol, sorgomol and orobanchol. 5-Deoxystrigol is more stable than hydroxy-SLs like strigol and thus susceptible cultivars might induce more germination of Striga seeds in the fields.
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謝 肖男, 米山 香織, 内田 健一, 横山 森, 来生 貴也, 横田 孝雄, 野村 崇人, 竹内 安智, 米山 弘一
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Strigolactones function as germination stimulants of root parasitic plants and hyphal branching factors of symbiotic arbuscular mycorrhizal fungi in the rhizosphere, and in plants they act as a novel class of plant hormones inhibiting shoot branching. In this study, characterization of strigolactones in rice (Oryza sativa L.) root exudate was conducted. Rice root exudate was found to contain strigolactones including orobanchol, 2'-epiorobanchol, 7-oxoorobanchyl acetate, two 5-deoxystrigol isomers and some novel strigolactones. One of the 5-deoxystrigol isomer was identified as ent-2'-epi-5-deoxystrigol by spectroscopic analyses, and purification and structure elucidation of the other novel strigolactones will be presented.
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米山 香織, 朝比奈 雅志, 野村 崇人, 横田 孝雄, 米山 弘一
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フリー
Strigolactone released from plant root stimulates germination of root parasitic plants and induces hyphal branching of arbuscular mycorrhizal fungi in the rhizosphere. In plant, strigolactone works as a plant hormone inhibiting shoot branching. It was already reported that phosphorus (P) deficiency promoted but P fertilization suppressed strigolactone exudation. In the present study, we demonstrated that auxin increased strigolactone exudation when rice plants were subjected to P fertilization, while cytokinin decreased strigolactone exudation when rice plants faced to P deficiency.
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原田 裕大, 謝 肖男, 米山 香織, 竹内 安智, 米山 弘一
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Plants belong to the Liliacae family such as onion depend largely on symbiosis with arbuscular mycorrhizal (AM) fungi for the supply of mineral nutrients due to their rather poor root systems. In this study, characterization of strigolactones produced by onion (Allium cepa L.) was conducted by comparing retention times of germination stimulants on ODS-HPLC with those of synthetic standards and by LC/MS/MS. The root exudates from onion plants were found to contain at least 4 strigolactones, orobanchyl acetate, 7-oxoorobanchyl acetate, ent-2'-epi-4a,8a-epoxyorobanchyl acetate (fabacyl acetate), and 5-deoxystrigol.
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